Very hot drinks increase the risk of oesophageal cancer, the largest study of its kind has concluded. Funded by Cancer Research UK and examining data from across the UK, experts found clear evidence of a link, though the overall risk is very small.
Study findings on drink temperature
Studies have previously linked hot drinks to oesophageal cancer but this is the most comprehensive to examine the issue. In it, people who said they enjoyed hot drinks had around a 1.7 times higher risk of cancer, while those who drank them very hot had around a three times higher risk compared to those who said they have drinks warm.
Consuming six or more hot drinks per day also pushed up the risk compared to drinking fewer than six. The study did not record the temperature of drinks but, in 2016, the International Agency for Research on Cancer classified drinking very hot beverages (above 65C) as “probably carcinogenic”.
How to reduce the risk
Letting drinks cool down before drinking or adding cold milk can negate the risk, experts have agreed. The new study said the temperature at which coffee and tea is drunk in Western populations is estimated to be around 60C.
Fiona Osgun, head of health information at Cancer Research UK, said: “While the risk of being diagnosed with this cancer remains relatively low in the UK, this research does add to the evidence that drinking very hot drinks could increase the risk of oesophageal squamous cell carcinoma.
“There is however a simple step people can take – let a cuppa cool down a little before taking a sip. And the most important ways to reduce the risk of this cancer type are not smoking and cutting down on alcohol.”
Research details and cancer types
Experts believe very hot drinks may damage the cells lining the oesophagus, which could increase the chance of cancer developing. For the new study, experts from Oxford Population Health at the University of Oxford looked at data from around 980,000 adults by combining two large UK studies – UK Biobank and the Million Women Study.
The two main types of oesophageal cancer are adenocarcinoma and squamous cell carcinoma (SCC). While drink temperature affected SCC risk in the study, there was no obvious impact on adenocarcinoma risk.
Overall, there are around 9,500 cases of oesophageal cancer in the UK every year. People in the UK have around a 1% lifetime risk of being diagnosed with SCC.
Dr Keren Papier, lead researcher and senior nutritional epidemiologist at Oxford Population Health, said: “International research has shown for some time that drinking beverages like mate at very high temperatures, as is typical in South America, is linked to increased risk of certain oesophageal cancers.
“What was less clear, was whether this also applied to the temperatures at which hot drinks are usually consumed in Western populations. This is now the largest study to look at that question in a UK population, where many people drink tea and coffee daily.
“It adds to existing evidence that drinking very hot drinks could increase the risk of oesophageal squamous cell carcinoma.
“More research is now needed to identify the exact drink temperatures linked to this increased risk.”
